Developing cover crop systems for California almonds: Current knowledge and uncertainties

Almond (Prunus amygdalus) orchard systems are highly productive and widespread in Mediterranean climates and dominate the California agricultural landscape. However, current intensive monocultural bare soil production practices limit the potential to support nonproduction functions (i.e., multifunctionality) and long-term sustainability of the orchard system (Aizen et al. 2019; Fenster et al. 2021). Managing orchards for multifunctional benefits includes maintaining ecologically and economically viable yields while prioritizing water quality, soil health, reduced input use, and support for biodiversity. Recent studies in almond demonstrate that diversification, including planted or spontaneous (resident) vegetation in orchard alleys, can improve multifunctionality by enhancing nonproduction functions in the orchard without reducing crop yield, thereby providing opportunities to enhance sustainability and resilience (Fenster et al. 2021; Morugán-Coronado et al. 2020).